Microbial production of fuel components from low-molecular weight gas mixtures

Abstract

Systems, methods, and metabolically engineered microorganisms are contemplated in which low molecular weight gases, and especially methane and syngas are used as a carbon source, and in which CO 2 or formaldehyde and reduction equivalents are generated for use in in vivo production of the value products.

What is claimed is: 
     
       1. A genetically engineered microorganism, comprising:
 a plurality of genes that provide enzymatic functions for (a) conversion of syngas or methane into reduction equivalents of CO2, and (b) C1 assimilation via CO 2 , using a CBB cycle; 
 wherein the microorganism is genetically modified to expresses at least one of the enzymatic functions from a recombinant gene where the genetic modification is at least one of
 (a) a recombinant gene that encodes an enzyme having CO reductase activity, 
 (b) a recombinant gene that encodes an enzyme having hydrogenase activity, 
 (c) a recombinant gene that encodes an enzyme having methane monooxygenase activity, 
 (d) a recombinant gene that encodes an enzyme having alcohol dehydrogenase activity, and 
 (e) a recombinant gene that encodes an enzyme having formaldehyde dismutase activity, and wherein the genetically engineered microorganism belongs to the genus of  Ralstonia.    
 
 
     
     
       2. The genetically engineered microorganism of  claim 1  wherein the genetic modification is a recombinant gene that encodes an enzyme having an activity selected from factor F420-reducing hydrogenase, F420-dependent methylene-H4SPT dehydrogenase, heterodisulfide reductase, methyl-coenzyme M reductase, methyl-H4MPT:coenzyme M methyltransferase complex, F420-dependent methylene-H4SPT reductase, 5,6,7,8-tetrahydromethanopterin hydro-lyase (formaldehyde-activating enzyme), or formaldehyde dehydrogenase. 
     
     
       3. The genetically engineered microorganism of  claim 1  wherein the genetically engineered microorganism is further modified to have a reduced aldehyde dehydrogenase activity. 
     
     
       4. The genetically engineered microorganism of  claim 1 , wherein the genetically engineeered microorganism to of the genus of  Ralstonia  is  Ralstonia eutropha.